cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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dm-space-map-common.h (4186B)


      1/*
      2 * Copyright (C) 2011 Red Hat, Inc.
      3 *
      4 * This file is released under the GPL.
      5 */
      6
      7#ifndef DM_SPACE_MAP_COMMON_H
      8#define DM_SPACE_MAP_COMMON_H
      9
     10#include "dm-btree.h"
     11
     12/*----------------------------------------------------------------*/
     13
     14/*
     15 * Low level disk format
     16 *
     17 * Bitmap btree
     18 * ------------
     19 *
     20 * Each value stored in the btree is an index_entry.  This points to a
     21 * block that is used as a bitmap.  Within the bitmap hold 2 bits per
     22 * entry, which represent UNUSED = 0, REF_COUNT = 1, REF_COUNT = 2 and
     23 * REF_COUNT = many.
     24 *
     25 * Refcount btree
     26 * --------------
     27 *
     28 * Any entry that has a ref count higher than 2 gets entered in the ref
     29 * count tree.  The leaf values for this tree is the 32-bit ref count.
     30 */
     31
     32struct disk_index_entry {
     33	__le64 blocknr;
     34	__le32 nr_free;
     35	__le32 none_free_before;
     36} __attribute__ ((packed, aligned(8)));
     37
     38
     39#define MAX_METADATA_BITMAPS 255
     40struct disk_metadata_index {
     41	__le32 csum;
     42	__le32 padding;
     43	__le64 blocknr;
     44
     45	struct disk_index_entry index[MAX_METADATA_BITMAPS];
     46} __attribute__ ((packed, aligned(8)));
     47
     48struct ll_disk;
     49
     50typedef int (*load_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *result);
     51typedef int (*save_ie_fn)(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie);
     52typedef int (*init_index_fn)(struct ll_disk *ll);
     53typedef int (*open_index_fn)(struct ll_disk *ll);
     54typedef dm_block_t (*max_index_entries_fn)(struct ll_disk *ll);
     55typedef int (*commit_fn)(struct ll_disk *ll);
     56
     57/*
     58 * A lot of time can be wasted reading and writing the same
     59 * index entry.  So we cache a few entries.
     60 */
     61#define IE_CACHE_SIZE 64
     62#define IE_CACHE_MASK (IE_CACHE_SIZE - 1)
     63
     64struct ie_cache {
     65	bool valid;
     66	bool dirty;
     67	dm_block_t index;
     68	struct disk_index_entry ie;
     69};
     70
     71struct ll_disk {
     72	struct dm_transaction_manager *tm;
     73	struct dm_btree_info bitmap_info;
     74	struct dm_btree_info ref_count_info;
     75
     76	uint32_t block_size;
     77	uint32_t entries_per_block;
     78	dm_block_t nr_blocks;
     79	dm_block_t nr_allocated;
     80
     81	/*
     82	 * bitmap_root may be a btree root or a simple index.
     83	 */
     84	dm_block_t bitmap_root;
     85
     86	dm_block_t ref_count_root;
     87
     88	struct disk_metadata_index mi_le;
     89	load_ie_fn load_ie;
     90	save_ie_fn save_ie;
     91	init_index_fn init_index;
     92	open_index_fn open_index;
     93	max_index_entries_fn max_entries;
     94	commit_fn commit;
     95	bool bitmap_index_changed:1;
     96
     97	struct ie_cache ie_cache[IE_CACHE_SIZE];
     98};
     99
    100struct disk_sm_root {
    101	__le64 nr_blocks;
    102	__le64 nr_allocated;
    103	__le64 bitmap_root;
    104	__le64 ref_count_root;
    105} __attribute__ ((packed, aligned(8)));
    106
    107#define ENTRIES_PER_BYTE 4
    108
    109struct disk_bitmap_header {
    110	__le32 csum;
    111	__le32 not_used;
    112	__le64 blocknr;
    113} __attribute__ ((packed, aligned(8)));
    114
    115/*----------------------------------------------------------------*/
    116
    117int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks);
    118int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result);
    119int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result);
    120int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
    121			  dm_block_t end, dm_block_t *result);
    122int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
    123	                         dm_block_t begin, dm_block_t end, dm_block_t *result);
    124
    125/*
    126 * The next three functions return (via nr_allocations) the net number of
    127 * allocations that were made.  This number may be negative if there were
    128 * more frees than allocs.
    129 */
    130int sm_ll_insert(struct ll_disk *ll, dm_block_t b, uint32_t ref_count, int32_t *nr_allocations);
    131int sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e, int32_t *nr_allocations);
    132int sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e, int32_t *nr_allocations);
    133int sm_ll_commit(struct ll_disk *ll);
    134
    135int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm);
    136int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
    137			void *root_le, size_t len);
    138
    139int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm);
    140int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
    141		    void *root_le, size_t len);
    142
    143/*----------------------------------------------------------------*/
    144
    145#endif	/* DM_SPACE_MAP_COMMON_H */